<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .barBox {
            margin: 50px auto;
            padding: 0;
            width: 600px;
            height: 20px;
            overflow: hidden;
            border: 1px solid #008fc8;
        }

        .barBox .bar {
            margin: 0;
            height: 20px;
            width: 0;
            background: repeating-linear-gradient(60deg, #9bcbff 0px, #9bcbff 15px, #008fc8 15px, #008fc8 30px);
            background-size: 35px 20px;
            animation: loading 1s infinite linear;
            transition: 3s linear;
        }

        .barBox:hover .bar {
            width: 600px;
        }

        @keyframes loading {
            from {
                background-position: 0 0;
            }
            to {
                background-position: 35px 0;
            }
        }
    </style>
</head>
<body>
<div class="barBox">
    <div class="bar"></div>
</div>
</body>
</html>